


One Rule

by daisysmalia



Category: Supernatural
Genre: Alternate Universe, Alternate Universe - High School, Angst, Fake/Pretend Relationship, Falling In Love, Fluff, Friends to Lovers, Humor, Idiots in Love, M/M, Miscommunication, Mutual Pining, Oblivious, Pining, Slow Burn, They are both so oblivious, They need to COMMUNICATE, They need to use words, based on a social media au I made on twitter
Language: English
Status: In-Progress
Published: 2020-12-14
Updated: 2020-12-23
Packaged: 2021-03-10 22:55:14
Rating: General Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 3
Words: 9,358
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/28075041
Author URL: https://archiveofourown.org/users/daisysmalia/pseuds/daisysmalia
Summary: “My ‘ground work’,” he replied, using air quotations, “Isn’t much at all. In fact, it is just one rule.”Cas’s rule was quite simple really and it was more to protect himself than anything to do with Dean.“Oh, yeah?” Dean asked, peering over the top of his mug, flashing a smirk in Cas's direction. “What is it?”“Under no circumstances can we actually fall in love with each other.”In an attempt to make his ex jealous, Dean asks Cas to be his fake boyfriend. Cas agrees, but sets one rule-whilst making their relationship look real, they need to make sure they don’t fall in love with each other. It’s easier said than done, especially when unearthed feelings are already there.
Relationships: Castiel/Dean Winchester, Charlie Bradbury/Rowena MacLeod, Eileen Leahy/Sam Winchester, Minor or Background Relationship(s)
Comments: 2
Kudos: 18





	1. Chapter 1

**Author's Note:**

> Hello! I'm writing and rewriting this fic based on a social media au I posted on my twitter account about six months ago, but I really wanted to write it in fic form too so here it is! If you want to read the completed version in social media au form you can here; https://twitter.com/daisysmalia/status/1232756858915622912  
> You can read it before, after or even at the same time as reading this version or you don't have to read it at all.  
> This fic isn't beta read, so I apologise if there is any spelling or grammatical errors.  
> Anyways, thanks for clicking and I hope you enjoy this fic, which I plan to update weekly if all goes to plan ;)

Dean fumbled around in his pockets, looking for his fake ID. It was cold outside and he’d rather be inside the bar with his friends than stuck outside in the dark, but the fairly impatient looking bouncer in front of him was certain on not letting Dean in without proof of identification. 

“It’s here somewhere,” Dean uttered, just loud enough to be heard, though even now he was losing hope of it being in his pocket. _Had Charlie even handed it to him?_

It had been his marvellous idea that they went to this new trendy sports bar in town. Bar 365 where all the cool kids hung out, and no he hadn’t suggested it because of rumours his ex-girlfriend, Lisa Braeden, was going to be there. Well, okay, that was one of the reasons he suggested it. But he also mentioned it because he wanted to have a good night out with his friends as they hadn’t all hung out together in a while. His brother had joked that Dean was only organizing this because booze was involved and so what? Booze made the nights fun. Sam had later agreed to come because it was a ‘sports bar’, so it would most likely be playing the big hockey game that he’d been talking about for weeks. Their friend Eileen, who Sam had the most blatant crush on, also agreed to come along and Dean then instantly knew the ‘hockey’ story was a cover up. 

Charlie had said she could get them all some fake IDs sorted before the night, and Dean was certain she’d given them out already. _So, why couldn’t he find his?_

He’d also had the stupid idea of letting everyone arrive on their own, in their own time so he couldn’t ask any of his friends for help as he didn’t know if they were already inside or not. And Sam had arrived with Eileen, so even his own brother couldn’t help him out. 

The security guard looked more unimpressed with Dean as the seconds went by and when he was about to give up and walk away from the line, he felt a hand on his shoulder. 

“He’s with me,” The voice said. Dean turned to see his best friend, Cas, stood beside him. 

“Here’s my ID,” Cas said holding out his fake credentials to the bouncer, “And here’s his. He left it in my car.” 

Dean raised an eyebrow and looked over to see that, sure enough, Cas had hold of his ID. Dean took it off him and flashed Cas a smile. The bouncer sighed and lifted up the rope to let the two boys in. 

“Thanks,” Dean whispered to Cas as they entered the loud and busy bar. 

Cas shrugged, “It’s what friends are for.” 

They both looked around the space before their eyes landed on the bright red hair of Charlie. She was stood up and eagerly waved at them. Dean and Cas made their way over to the table and Cas sat himself down in a gap besides Sam and Eileen. Dean remained standing and put his hand on the table. 

“Okay, what does everyone want? First round is on me!” 

*** 

Cas took the last mouthful of his coke before placing the empty glass down in front of him. He could hear Sam next to him trying to explain why the hockey game was so important to Eileen, who was sat wide eyed nodding intently to everything that was said. He could hear her giggle at whatever was being said or done by Sam as his ASL was still not up to scratch. Eileen still wouldn’t let him live down the time he’d accidentally signed ‘fuck you’ instead of ‘thank you,’ when they first met. Cas presumed a dark rouge blush must’ve crept over Sam’s cheeks like it always does when he’s with Eileen. He knew Eileen didn’t really care about the hockey, but she seemed interested because it meant something to Sam. It was obvious that they liked each other. Everyone could see it but them. Maybe, Cas thought, he should try help push them together. He’d have to ask for Dean and Charlie’s help but it could work. _It's_ _what friends are for, right?_

He turned his head in the direction of the busy bar, it was loud and he could see Charlie mingling in the middle of a bunch of people. Most of them were other students. Cas wasn’t surprised that Charlie was back on her quest to find a girlfriend. It was something she often did when they went out as a group and though she hadn’t had much luck yet, she was positive this method would help her find someone in the future. She caught Cas’s glance and beckoned him over to join her, but with a polite smile Cas shook his head. Charlie turned away, back towards a girl she’d been talking to with blonde hair and Cas watched as she tucked a strand of hair behind her ears. He found it quite strange that all of his friends were searching for relationships right now when they still had so much time for that. Cas wasn’t really interested in love or relationships and Charlie had always said it was because he _‘wasn’t considering the right person’-_ whatever that was supposed to mean. And though his outlook on love was bleak, he only wanted what was best for his friends. For them to be happy. 

Cas had been the one to tell Dean that his ex would be at the bar tonight, and he’d regretted doing so the moment the words left his mouth. Lisa was a nice girl; she was pretty and sweet but she hadn’t been right for Dean. Their break up had left Dean reeling for several weeks and Cas had been the one there for him. Cas was always the one there for Dean after his breakups. Dean hadn’t dated anyone for a while, not since Lisa. 

Cas surprisingly was yet to see Lisa tonight even though Anael, a friend of his, was certain that she would be there. He wondered what Dean’s reaction would be when he saw her, if they’d make a scene or even end up leaving together. It wasn’t that he was jealous or anything- Cas just didn’t think they were a good match, none of their friends did. Dean was never happy when he and Lisa were together and they had rarely seen him. Nights like this were a regular occurrence before Lisa came along, and Cas was happy that they were back to how things use to be. His mind began to wonder if Dean would genuinely try get back with Lisa if he saw her again. Cas was unsure of the reasons behind their break up, but he still didn’t think Dean was over it. 

Cas was slightly lost in his thoughts when he felt a firm hand on his shoulder. He quickly turned his head to see Dean hovering next to him. His deep green eyes staring into Cas’s own blue eyes. There was a mild stench of alcohol coming off of Dean, and Cas was unsure about how much his friend had drunk. 

“Can I not persuade you to drink anything exciting?” Dean asked, before lowering his head and grinning, “I hear they do a mean Sex on the Beach.” 

Cas chuckled at what had been said, but shook his head. Dean tilted his own and flashed his signature puppy eyes at him which he often resorts to when he wants something. It was clearly in a playful manner, so Cas just laughed it off. 

“You can get me another Coke, if you want?” Cas said, holding out his glass. Dean sighed but took the glass off of Cas with a small smile. 

“One Coke coming up for the most boring person in the room. The most boring person I know,” Dean joked, quite loudly, stepping back from the table and almost tripping over his own feet. 

“I’m probably the only boring person you know,” came Cas’s response, he had to speak up a little to make himself heard. 

Dean took another step away from the table and grinned. 

“Yeah, but I wouldn’t have it any other way.” 

Cas smiled to himself as he watched Dean bundle through a crowd of people and walk over to the bar. He could still hear Sam and Eileen next to him still deep in conversation and he slouched back into his chair at ease. Maybe Dean was right, tonight would be one of the best nights ever. He closed his eyes. He probably should’ve taken Dean’s offer up with the cocktail, if it wasn’t too late, maybe he could go order with him. 

*** 

Dean wasn’t back after five minutes and he wasn’t back after ten either. Cas turned on his phone, assuming the queues for ordering must have been long and opened up a text conversation with his brother, Gabriel. 

**G: Are you bored yet, Cassie?**

Cas raised his eyebrows at the text which Gabriel had somehow sent before Cas had even set off to the bar. 

**C: Maybe a little bit.**

It took Gabriel mere seconds to reply. 

**G: I did warn you.**

Cas rolled his eyes. His brother had not shut up about how boring all of Cas’s plans had sounded. Going on about how wasting money on getting yourself intoxicated was not a fun way to spend a Friday night. Cas wondered where Gabriel had even gotten this impression from because it certainly wasn’t experience. He and Anael were Gabriel’s only friends and as Gabriel’s brother he probably didn’t really count. So, Gabe’s list of friends was really a mere one person. 

**C: I’m just sat here staring at an empty glass. Sam and Eileen are staring at each other beside me. All gooey eyed.**

**G: Where’s Dean?**

At his brother’s text Cas glanced back over to the bar to see if Dean had been served yet, but was stopped in his tracks. He had to do a double take. 

Dean was stood at the bar as expected. Next to him stood shorter woman, she was laughing almost hysterically at something dumb Dean had probably said. Dean had a wide grin spread across his face and his eyes were almost fixed on the girl in front of him. Lisa. 

Cas didn’t feel like replying to Gabriel anymore so instead placed his phone into his pocket before pushing himself out of the booth. He turned to Eileen and Sam to tell them where he was going. They were sat as close to each other as they possibly could and it appeared that Eileen’s head was resting on Sam’s shoulder as they both intently gazed at something on Sam’s phone. It didn’t seem like they would notice his absence, so Cas decided to continue to where Charlie was without making a fuss. He made sure to avoid eye contact with where he presumed Dean and Lisa still were. 

Cas instantly noticed Charlie due to her vibrant hair and wandered over to her, expecting her to be with the girl she was with earlier. Instead, he found her alone, cradling a shot glass in her hand. 

“Where’s she gone?” Cas asked, raising an eyebrow, gesturing to where the girl had been before. 

“She was straight,” Charlie sighed, her words slightly slurred, “Why are they always straight?” 

Cas placed a supportive hand on Charlie’s shoulder whilst she pouted. 

“C’mon, I’ll help you find someone else.” Charlie’s lips curved up at Cas’s suggestion and she placed the shot glass down in front of herself. 

“Thanks, Cas. You know, I could help you too- everyone knows that most iconic lesbian and gay alliance is right here,” she exclaimed, waving her finger between the two of them. Cas let a small smile fall to his lips, but before he had a chance to respond Charlie began to speak again. 

“Where’s Dean, by the way?” She pushed herself onto her tiptoes and began to crane her neck around the room. 

Cas shuffled awkwardly on his feet, and rubbed his spare hand on the back of his neck, “He’s at the bar with Lisa.” 

Charlie’s face changed instantly, her mouth opened wide and her eyes flashing with disbelief. 

“Wow, I didn’t see that coming...I thought he’d...” she paused, “I thought he was over that and has moved on...” 

“Well, I mean he’s just talking to her, he might’ve...” Cas added, but who was he kidding. Charlie’s expression changed once more, to something Cas couldn’t quite read- it almost seemed like sympathy. Charlie carefully pulled Cas’s hand off her shoulder and held it in her own whilst glancing back towards their table. 

“Why don’t we go back and see what the two love birds are up to?” she said, “If they still haven’t gotten their act together and announced their undying love for each other I’m going to have to lock them in a room or something soon.” 

This brought back Cas’s smile, it seemed Charlie would be in on any plan he had to get Sam and Eileen to finally confess how their feelings for each other. Charlie suddenly began to march over to their table. She still had a hold of Cas’s hand and so was dragging him with her. Cas struggled to keep up with her. They were pushing through a large group of quite obviously drunk men and eventually he had to let go of Charlie’s hand. That was when he felt a familiar hand on his shoulder. Dean was stood by his side. No sign of Lisa. 

“Cas,” was all he said, not a ‘ _sorry for leaving you’_ or an explanation. Cas rolled his eyes. 

_“Sorry, I left you. Here’s your drink,”_ Cas replied, sarcastically, avoiding any eye contact with Dean to make sure Dean knew he was annoyed at him. Dean let out a quiet wheeze. 

“Yes, I’m sorry about that,” Dean started, moving so he was in front of Cas, therefore making eye contact inevitable, “But I need a favour.” 

Cas folded his arms across his chest and grunted, “Let me guess. You need me to cover for you when you leave with Lisa tonight. Instead of leaving with us,” he stated, scowling, “Yeah, well no, I’m not going to cover for you this time.” 

Dean began frantically shaking his head, he looked quite panicked and Cas finally realised Dean’s pupils darting around the room. It seemed he was also avoiding any eye contact. Cas raised his eyebrows in confusion. Dean shuffled awkwardly on his feet. 

Dean took a deep breath. 

“I need your help. Yes, this is to do with Lisa but not how you think...I just...I... I wasn’t thinking and I wanted to make her jealous...” Cas groaned and felt like walking away. He didn’t want to have to deal with this today. Of course, Dean wanted Lisa back. Of course, he’d probably grovelled to her about how much he missed her forgetting the mess he was in after the break up. Cas began to twist his body away but before he could even move seven words left Dean’s mouth. Seven of the most unexpected words. 

“I might’ve told her you’re my boyfriend.” 

**Notes for the Chapter:**

> Dean....
> 
> Thanks for reading the first chapter, I hope you enjoyed it and stick around for more.  
> Love, Leah <3


	2. Chapter 2

**Summary for the Chapter:**

> Dean wakes up hungover, the night before slightly hazy.  
> Cas wakes up still annoyed, the night before vividly in his mind.

Dean awoke the next day with a pounding headache. He could feel the heavy rush of blood and groaned. He pulled the pillow over his head as though it would somehow stop everything that was hurting. He had definitely drunk too much last night. After Cas had left, (because he had messed up) Dean hadn’t stopped drinking. Shots. Vodka. Whisky perhaps? Mixing drinks had to have been one of the worst ideas he’d ever had because now it felt like cement was being drilled inside his head. And yet, it hadn’t even been the worst idea he had had last night. That crown went to his stupid mouth telling Lisa that Cas was his boyfriend, all in a pitiful attempt to make her jealous- or at least he assumed it was that, the conversation itself was hazy. 

The disapproving expression that had spread across Cas’s face said it all. Cas had already been annoyed that he had left him to talk with Lisa in the first place and then he’d come over and told Cas something he probably never wanted to hear. Dean couldn't fully remember the rest but he wouldn't put it past himself to have then dug himself into an even deeper hole. In fact he had. Instead of waiting for Cas to reply to his first comment, he had blurted out that they could ‘flow with it’. _Fake date._ In some attempt to fix the situation. It didn't and Cas left the bar shortly after.

Dean groaned even louder as the memories came back to him. He reached over to his bedside table and felt around for his phone almost knocking over a glass of water. He picked the phone up and turned it on and was slightly disappointed to see no new messages. His text conversation with Cas was still open, but the only recent activity had just been him spamming Cas’s name in a drunken state in hope that his friend would reply. 

Dean let out a loud grunt at his drunken self's actions before typing out another message to Cas. 

**D: I’m sorry about last night...and what happened...and what I said. Just please message me back if you see this.**

**D: Even if it’s you telling me to fuck off.**

*** 

Cas had woken up early and decided to go for a run. He’d remained sober, so the events from last night were vivid in his head. He tried to shake them but Dean’s words rang clearly in his ears. 

_I might’ve told her you’re my boyfriend_

Cas couldn’t understand why Dean had done it, nor did he really want to know. Deep down he knew the most likely scenario was it had been done in an attempt to make Lisa jealous. Dean often didn’t think straight when he was intoxicated and this was most likely one of them situations. Cas could recall a time from when the two of them were younger, and they’d both found Mary Winchester’s whisky cabinet. They had managed to get so drunk that the whole night was a blur. Mary had found them upside down in the living room, both complaining about the worst headaches they had ever head. But the most embarrassing part was finding out on Monday that they’d somehow prank called their teacher and said some things they deeply regretted now. Apparently it had been Dean's idea and he had taken most of the heat for it, but Cas couldn't say if that was true or not, he couldn't remember anything from that night. It was the first and last time Cas had ever drunken alcohol, and he'd sworn to be sober ever since. 

When he got back from his run, he switched on his phone to find a plethora of texts from Dean and sighed. 

**C: I wouldn’t tell you to fuck off.**

Cas replied, rolling his eyes at Dean’s initial comment. Trying not to smile at Dean's ridiculous statement because he was still mad at him. However he'd never tell him to fuck off even as a joke, Dean meant too much to him.

**D: Oh, he speaks!**

Dean's response came almost instantly to which Cas found himself rolling his eyes even more. He guessed Dean must've been hovering over his phone waiting for Cas to reply, which was sweet but Dean had gotten himself into this mess to begin with.

At that moment his phone began ringing. An upbeat remediation of 'Under Pressure' started playing and Dean’s photo was gazing at him through the screen. Cas sighed again, reluctantly answering the call. 

“Seriously Dean?” he groaned. “What?” 

“I just want to say again how sorry I am...” Dean said, trailing off, “For leaving you to go talk to Lisa and for what I said to her, and probably for other things I can’t even remember.” 

“Oh wow, what a heartfelt apology,” Cas jeered back sarcastically. 

“I’m sorry, you know I’m not good at apologising,” Dean replied and Cas could almost hear the puppy dog eyes he was certain Dean was pulling on the other end of the phone. Imagining that made Cas blush and he knew he couldn't stay mad at his best friend for a second longer.

“Okay. Okay. You’re forgiven dumbass.” 

Cas was certain he heard Dean quietly cheer. 

“Right, now that’s out of the way...I’m going to go and make myself some breakfast,” Cas said, “And because I know you won’t have yet, you should make yourself something too. Best cure for a hangover is food.” 

Dean didn’t reply for a moment and Cas was prepared to hang up when he heard his best friend’s voice once more. 

“Wait...the other thing...I need your help,” Dean paused, “Can you be my boyfriend?” 

Cas almost dropped his phone. 

“Well... not my real boyfriend...my fake one...because of you know what I said, I think it has travelled fast and... I don’t want Lisa to think I lied to her and now everyone probably thinks we are dating. So, please?” 

Cas didn’t know what to reply- how to reply. This was the second time Dean was proposing they ‘fake date’ and this time he was completely sober. Cas didn’t know what to think. Or why he was thinking at all. Why was he even considering this? Should he be considering it? 

Cas hung up. 

*** 

The sun shone through the trees and the birds sung in the branches. The streets were fairly empty for a Saturday morning but Cas appreciated the peace and quiet. He was already on the second walk of the day, to try and clear his head, but it wasn’t exactly working. He couldn’t get his mind off of Dean. Well, what Dean had suggested. Cas didn’t even know why, the simple thing to do would be saying _‘sorry, I can’t.’_ But Dean was his best friend and something in his gut was telling him he should help. 

Cas pushed open the door to the small coffee shop which Anael, a family friend, owned. It was a snug building, and wasn’t overly busy. He’d come here immediately after hanging up his phone, ignoring the ping of texts from Dean. Cas had decided he needed some advice and Anael always seemed to tell him exactly what he needed to hear. 

He glanced around at the tables which were filled with a few customers and was surprised to see his brother, Gabe, sat amongst them. He was writing something on his laptop and taking a bite out of an apple. Over at the counter Anael had noticed Cas. She was serving a customer and signalled for him to go sit down somewhere, suggesting she’d come over and see him afterwards. He often arrived like this without warning and Anael would always know that Cas wanted a one on one. It was like she could read his mind.

Whilst he waited, Cas walked over to his brother’s table. 

“I didn’t expect to see you here,” he said, resting his palm on the table. 

“I’m always here. You just don’t notice,” came Gabriel’s reply, he didn’t take his eyes off his laptop screen, “I told you I have no friends, apart from Anael, so I like to spend my time here. It’s peaceful, I can write and I’m helping out a local business.” 

“Thanks for the charity, Gabe,” came a sarcastic reply from behind. Anael was stood there smiling. She was wearing a pink cardigan and a blue dress. Her red hair glowing in the sunlight that streaked through the windows. Anael held out two cups of coffee. One for Cas and one for herself. 

“Now if you’ll excuse us, me and Cassie need to talk.” 

Gabe rolled his eyes and went back to typing on his laptop. 

“You could come to me, your brother, for advice one day, you know?” Gabe said as Cas and Anael moved to a nearby table. Cas just chuckled under his breath, remembering all the bad advice his brother had given him over the years. It always came in the form of some weird analogy or metaphor and then Gabe would try use the situation in his new book idea. Cas knew his brother meant well, but he felt much more comfortable getting advice from Anael. 

Anael leant forward in her chair whilst taking a sip from her cup, “So, what’s playing on your mind today?” 

Cas looked down into his own mug and began to stir his spoon. 

“I’m pretty sure Dean wants to get Lisa back,” he stated, letting out a sigh, “And his stupid plan involves pretending I’m his boyfriend to make her jealous, or something.” 

Anael raised her eyebrows and leant back in her chair, she carefully placed her cup down on the table in front of them. It clinked on a saucer as she did so. 

“Wow,” she replied, “And how do you feel about that?” 

Cas shrugged his shoulders, “Well it feels like he wants to use me, even though he probably doesn’t. I mean he hasn’t even said it’s to get Lisa back, he just said it’s because news travelled fast but I’m not stupid. I can put two and two together.” 

Anael nodded. “So, you’re not going to do this.” 

“I didn’t say that...” 

“Listen Cas, you should do whatever you think is best. Whatever feels right for you. Listen to your head, not your heart. But Dean’s your best friend, I highly doubt he wants to use you, I promise.” Anael said her hand hovering between her head and heart to signal what she meant. She flashed him a supportive smile, which Cas couldn’t reciprocate. 

Cas closed his eyes and took a deep breath before thinking long and hard. Anael was right, he had to do what he thought was best, and yet the only thing that seemed right to him was helping Dean. Because she was right, Dean was his friend and he wanted him to be happy and that was really all that mattered to him. He’d get to spend more time with Dean too before the inevitability of Lisa returned. Maybe it could benefit him too. _Maybe_. 

Anael’s chair scraped along the floor as she pushed it back to stand up, bringing Cas out of his trance. 

“I should get back to my shift,” she said, beginning to walk back to the counter. She moved past Cas and placed a supportive hand on his shoulder. “Sorry if my advice wasn’t helpful.” 

Cas shook his head with a small smiled. 

“No, it helped.” Cas tilted his head upwards and the corner of his lips turned up. “Thanks.” 

“I’m always here for you, Cas.” 

Anael ruffled Cas’s hair and flashed a smile back before walking back towards the counter. Cas looked down timidly before reaching into his pocket and carefully pulling out his phone. He unlocked it and went into his messages. Cas knew what he was going to say to Dean. He was following his head, like Anael had said. He just needed to set a few things straight. 

**C: I’ll do it.**

**C: I’ll pretend to be your boyfriend.**

Dean’s response was instantaneous 

**D: Wait, really? Thanks, Cas. I promise I’ll repay you one day.**

Cas chuckled to himself. _Sure,_ _he would._

**C: I’m at Anael’s. Come meet me, I** **wanna set some groundwork.**

*******

Dean pushed the door open to Anael’s café and glanced around. He'd arrived as soon as he could, running over as he still felt too tipsy to drive. His hair was still slightly wet from a shower he'd had and he'd thrown on the closest t-shirt he could find, which didn't seem to fit him properly. Dean noticed Cas sat on a table with two steaming cups placed in front of him. He was in deep conversation across the room with Anael who was stood at the nearby counter. Cas had seen Dean enter and gave him a polite wave, ducking his head whilst doing so. Dean made his way over to him and pulled out the chair. Cas promptly ended his conversation with Anael and turned to face Dean, either not noticing or deciding not to comment on the rugged state Dean was in. Cas's expression was bland and difficult to read, so Dean flashed him a grin in attempt to cheer him up. Instead it caused a light blush to creep over Cas’s cheeks which he tried to hide it with a frown, but Dean knew Cas too well and just wiggled his eyebrows in turn.

“I think you’re a good actor,” Dean observed in relation to the situation. Cas looked back puzzled. “Which...is a good thing if we want to make this seem real.” 

Cas nodded slowly, realising what Dean was talking about and instead of joking back, Cas decided it was time they spoke business about the whole situation. 

“Dean, we need to clear some things up first,” he replied, leaning forward. His voice almost becoming a whisper, “I mean have you even considered the fact we’ll have to fake it in front of our friends? Your brother?” 

Dean raised an eyebrow, drumming his finger on the table. 

“Isn’t that fun?” 

Cas looked back, not sure whether Dean was being serious or deadpanning him. 

“No?” 

“It is a bit,” Dean replied, a small grin on his face, “Plus, us being ‘together’ might push Eileen and Sam to go and get their act together.” 

Cas tried to remain serious but couldn’t help chuckling. So basically, everyone could see that Eileen and Sam were in love with each other but them. They were so oblivious it was quite funny. Maybe Dean was right, maybe this would push them together like Cas was already planning to try do. 

“Tricking our friends is one thing but when are you going to be able to see Lisa so she knows it ‘is real?’ Cas asked, raising his eyebrows. 

“I’m not sure yet.” 

“Well, I mean that’s what this is all about, isn't it? Making her jealous,” Cas replied, folding him arms across his chest and tilting his head slightly, “Come on, Dean. I know you.” 

“No, it’s actually...fine you got me,” Dean said, “But we’ll cross that bridge when we get there, eh?” 

Cas nodded, slightly uncertain, slumping back in his chair. He placed his hands back on the table and began to fidget with a few packets of sugar that were laid out in a line in front of him. 

“Are you find with PDA?” Dean asked. Cas nodded in response without looking up, barely even taking in Dean’s words. “Well, all we have to do really is hold hands but if that’s okay in your ‘ground work’ or whatever then...” 

Cas slowly glanced up at Dean and saw a mischievous smirk spread across his face. 

“My ‘ground work’,” he replied, using air quotations, “Isn’t much at all. In fact, it is just one rule.” 

Cas’s rule was quite simple really and it was more to protect himself than anything to do with Dean. 

“Oh, yeah?” Dean asked, peering over the top of his mug, “What is it?” 

“Under no circumstances can we actually fall in love with each other.” 

Dean placed his cup down and nodded, Cas couldn’t read the exact expression across his face but Dean seemed to have taken his words in seriously so that was that. 

“We’re mates and this isn’t real, so I’m sure we’ll be fine,” Dean finally replied though there was a change in his tone. Harsh. Hurt? It was there for a split second but he was back to joking almost instantly. “But are you sure you won’t fall in love with me? I’m pretty irresistible.” 

Cas rolled his eyes and shook his head at Dean’s confidence. Trying his best to not laugh. 

“Lisa begs to differ.” 

“Ouch...ouch...Castiel you have wounded my ego,” Dean teased back. 

Both boys burst into hysterics. Dean throwing his head back and laughing more than Cas had seen him do so in a while. His comeback hadn’t even been that funny but it was nice to see Dean like this and to be spending time with him. Cas wouldn’t admit it but he had missed it being just them and now he’d be spending a lot more one on one time with Dean in the future. 

“So, when are we going to tell our friends we got together?” Cas asked, messing with the sugar packets once more. Dean leant back in his chair, folding his arms as though that would make it easier to decide. 

“We could say Friday night? Say I was drunk and admitted I loved you or something?” Dean replied, it made sense and was moderately believable. 

“And we can pretend that I’ve always been deeply and madly in love with you but I never had the courage to say it, until I saw you with Lisa and got jealous,” Cas chuckled slightly and gave Dean a knowing eye whilst mentioning Lisa. “And then like every fairy tale story we got together, but this one won’t have a happy ever after...” 

Dean had started to take a drink out of his coffee but stopped at what Cas had said. Almost choking. He looked up. 

“It won’t?” 

Cas shook his head with a little laugh, “I mean we can’t pretend we’re dating forever. Besides once Lisa is jealous, you’ll win her back easily.” 

Dean paused; his mind had gone blank. Cas was gazing at him intently. In the end Dean just shrugged his shoulders giving a hasty response, “So how long you willing to do this for?” 

Cas glanced out of the window beside them. The sun shone through onto the side of his face. His ocean blue eyes glimmered as they reflected the light and Dean noticed one of Cas’s curls had fallen onto his forehead. Dean sat back admiring his friend. Watching as the thoughts whirred through Cas’s head. He’d often done this, just observed Cas from a far. He didn’t know why he did it but he could never stop himself from doing so, every now and then his eyes would just linger on his best friend for longer than they probably should. Dean kept his focus on him until Cas promptly turned his head back and Dean in turn had to awkwardly look away. 

“A month.” 

Dean slowly nodded at Cas’s admission. A month could work. They’d see their friends plenty of times in the next month and the school dance was coming up in that time frame so he could ask Cas to go as his date. _His fake date._ Lisa would most likely being going too, so there they could carry out the reason why they had even agreed to do this in the first place. The reasons Cas believed they were doing this. And in this month, he could spend plenty of time with Cas, because after they inevitably pretend to break up from their fake relationship, it would seem weird if they hung out as much immediately after. 

“How will you last a month without falling in love with me?” Dean teased once more with a wry grin, taking another mouthful of his coffee. Cas tilted his head but couldn’t hide the smile that had found its way to his lips. 

“I won’t fall in love with you if every time you drink...” he trailed off before pointing to Dean’s upper lip, “...you do that.” There sat a line of frothy foam from his drink, which looked like a creamy moustache. It took a moment for Dean to realise what Cas meant but then his eyes lit up when it hit him sending Cas into laughter once more. 

Cas carefully picked up a napkin, leant across the table and wiped off the remnants of drink from Dean’s face. 

“Here let me. It’s what boyfriends are for right?” He joked. Dean let him wipe it away and was in awe at how gentle Cas was being with him. Dean found himself leaning into Cas’s touch and was startled when he pulled his hand away. As Cas leant back, Dean sent him a thankful look and unintentionally traced the area above his lips with his finger. 

“So, then...has my acting improved. Do you think I make a good fake boyfriend?” Cas asked, clearly teasing. Dean had a strange sensation in his chest that he couldn’t quite put his finger on. His heart pounding much faster than normal. He put it down to being touch starved, he hadn’t been that intimate and close with anyone for a while. 

“That was an act?” 

Cas nodded, “Well, you did actually manage to have foam all over your face, but normally I wouldn’t even tell you until we’re out in public. I’d let you try flirt with someone attractive and embarrass yourself,” Cas shrugged, nonchalantly, seeming proud of himself. “You were taking this whole thing seriously so I decided to up my game too.” 

Dean shook his head with a grin, slightly embarrassed that Cas knew him so well. Slightly embarrassed he hadn’t realised that nearly everything they’d end up doing for the next month would all be part of some act despite the fact this had been his idea. His drunken idea. At least they both knew it was fake, so anything that did happen couldn’t blur the lines of their friendship. Actions like that were all an act, so things hopefully wouldn’t be awkward when the whole scenario was over. His heartbeat was still faster than he’d like it to be so Dean picked up one of the sugar packets Cas had been playing with and twiddled it between his fingers as a distraction. He flickered his gaze back up towards Cas, who still looked pretty pleased with himself. Dean scoffed, but couldn’t help looking at Cas with full admiration. 

“Well then Novak,” he replied, “I think you play the part just fine.” 

**Notes for the Chapter:**

> So they're going to do it. They're going to try and date each other for one month, of course with their rule in place it should be easy.  
> Thank you for reading, I uploaded this chapter earlier than I planned so I'm not sure when I'm going to be posting the next chapter. Thanks for reading,  
> Love Leah <3


	3. Chapter 3

**Summary for the Chapter:**

> Two plans are set in motion.

When Cas arrived home that evening, he instantly sunk into a chair. He replayed certain moments including wiping the froth from Dean’s face. He didn’t really know why he’d done it, it just felt right-like something he should do. Maybe he was better at this whole fake dating schmitt than he first thought he would be. Cas slumped further back in the chair, or maybe he’d done it because he wanted to. The look on Dean’s face had been worth it either way but now Cas couldn’t get the moment out of his head. _Why had he agreed to do this?_ It wasn’t like he was oblivious to the tiny little crush he had on Dean. He was attractive and had always been there for Cas, but that’s all it was a tiny crush. Not even that, it was just a few butterflies. 

Cas groaned out loud. He really shouldn’t have agreed to this. 

At that moment his phone began to ring, it startled him and he frantically reached towards it. He was only a little bit disappointed to find Charlie was the one calling him. Cas had assumed it’d be Dean. 

“Uh hello Charlie,” Cas said after answering the call. 

“Hey,” Charlie responded, “I was beginning to think you were ignoring me or something. Where’d you go last night? You were there one second and the next you were gone!” 

Cas twiddled with his thumbs, he was so angry last night he had just left without telling anyone and then he’d been so wrapped up in this Dean thing that he hadn’t replied to any of his other texts either. 

“Sorry about that, I spoke to Dean about something and then left.” 

Cas could hear Charlie make a strange sound at the other end of the phone, but couldn’t make out exactly what it was. 

“Oh, cool, cool,” she finally replied before changing the topic, “Right, so you know we spoke about getting Sam and Eileen together, well I have a plan.” 

Cas arched an eyebrow. 

“Do tell.” 

“Unfortunately, I cannot reveal all my secrets, though it does involve us all going out for a meal at Benny’s tomorrow...so I’m just checking you can come?”

“Yeah, I think I can,” Cas replied and without even thinking, “Is Dean invited too? Um...I mean can he be involved in this whole get-Sam-and-Eileen-together malarky?” 

“Of course,” Charlie said, pausing slightly, “So you and Dean are okay?” 

“Yeah, why wouldn’t we be?” 

“I though because of Lisa...” Charlie seemed like she had more she wanted to say but stopped herself, “You know what, never mind. Right. Operation lovebirds is a go and then, if this works maybe I can try be your wing man.” 

Cas could practically here Charlie wink at him down then phone and laughed. 

“Thanks... but I don’t think I need you to be anymore.” 

“WAIT WHAT!?” came a screaming Charlie down the phone, but Cas refused to spill any details no matter how much she pushed. Eventually Charlie gave in and wished Cas a good night before hanging up. Cas chuckled to himself at how invested Charlie was in her friends love lives, maybe next they should try help Charlie with hers. 

Before Cas went to bed, he made sure to text Dean about the plans for the next day. 

**C: Charlie told you about tomorrow?**

**D: Yup, looking forward to it**

Cas smiled and took a moment before typing his response. 

**C: Are we going to tell them tomorrow?**

**C: About ‘Us’ I mean?**

Cas made sure he added quotation marks around us. 

**D: Sure thing, let the fun begin** **😉**

Cas couldn’t help rolling his eyes, but there was a smile across his face. 

**C: Good night Dean.**

**D: Night Cas**

*** 

Dean pulled his car into a bay at the parking lot. It was a large, black Chevrolet Impala, which he would label as his prized possession. A car he’d worked on with his father before the man had walked out on him and his brother’s lives. She meant a lot to Dean and there weren’t many things in the world he loved more than her. 

Dean turned to face Cas, who was staring at his phone screen. Cas held his phone up to Dean’s eye line so he could see the plethora of texts that Charlie had sent him, asking where they both were and informing them that they were late. Very late. The last text was a bit of cry for help as she apparently starting to feel very much like a ‘third wheel’. Dean chuckled to himself, imagining Charlie stuck alone with Sam and Eileen. The pair were probably just staring at each other longingly like usual and Charlie, no matter how much she wanted them together, probably wanted the ground to swallow her whole. 

Cas had been surprised to find Dean at his door when he was about to set off to Benny’s. They hadn’t planned on arriving together but Dean had leant against Cas’s porch and with a wink claimed he’d wanted to be ‘chivalrous.’ Cas was surprised Dean even knew what the word meant. But he had eventually agreed that Dean had the right idea. If they really wanted to make people believe that they’re together, they had to act like a couple. Plus, a lift to Benny’s with Dean was a much better prospect than having to walk there alone. And secretly Cas always enjoyed rides in Dean’s impala. He likes how it smells. 

“So, are you ready to tell them, about ‘us’?” Dean said using air quotations just like Cas had done previously. He ran a hand through his hair, pushing it backwards whilst waiting for Cas’s response. 

Cas just nodded. 

“I’ve always wanted to say this,” Dean added now rubbing both of his hands together with a smirk. Cas rolled his eyes and after a moment of fiddling with the handle he pushed open the car door. 

“Wait at least a few minutes, yeah?” 

*** 

Cas walked into the restaurant. He took a deep breath and he strolled towards the table where his friends were sat. He felt slightly apprehensive and it was only now dawning in him how difficult it’d be lying to them. To everyone. Charlie was anxiously drumming her fingers on the table, whilst Sam and Eileen were in some deep conversation. When Charlie noticed Cas approaching, she jumped up out of the booth and brought him into a brief embrace. When she pulled back it was clear to Cas that she was rather annoyed. 

“You’re late,” she bluntly stated, before lowering her voice, “And you left me alone with the two love birds, it’s making me jealous. I just want a girlfriend.” 

Charlie threw her arms up in exasperation and all Cas could do was smile apologetically. 

“Sorry, I um...I didn’t mean to leave you...” Cas trailed off and noticed Sam and Eileen has stopped their conversation and were now watching himself and Charlie. Charlie was now stood with her arms folded, tapping her foot on the floor. She raised her eyebrow, seemingly waiting for more answers from Cas. Answers she was sure to get sooner or later. Charlie was about to speak up once more but was cut off by Sam. 

“We can moan at Cas for being late, but my brother isn’t here yet either,” he stated, Eileen nodding coherently. Charlie rolled her eyes before sliding back into the booth and patting the space next to her for Cas to sit down too. Cas followed and looked ahead out of the large diner windows; he was surprised none of them had noticed Dean’s impala which was clearly parked outside. Cas could feel Charlie’s eyes on him but she had yet to look in the same direction. 

“I can moan because this was supposed to perfect. I had everything planned out!” 

Cas hadn’t yet realised how seriously she was taking this ‘get Sam and Eileen together mission’ but it was clearly stressing her out. Eileen and Sam just watched on, slightly confused by Charlie’s outburst. Cas began to wonder how Charlie would take the ‘news’ about him and Dean, and even how she’d react if it was ever revealed that it wasn’t real. But all he could do was think of these scenarios because the plan was already in motion and he had no time to back out. The door to the restaurant had opened behind them and a gust of wind blew inside.

“So why were you late?” She questioned again, sounding like the mother hen that they all knew she was. Cas sighed, and replied with what Dean had begged and begged for him to say on the way there. He didn’t even know how Dean had made him agree to this, but eventually he had. Albeit reluctantly. 

“I was busy doing things...” 

At that moment a firm hand was pressed against Cas’s shoulder, a touch that he was so familiar with. One he could feel himself melting into. But at the same time everything felt so much different, the situation so different. 

“Hi, I’m things.” 

Dean was now stood behind him and broad smirk was plastered across his face. Cas didn’t know how to act until he saw the reactions of his friends. Sam’s eyebrows were raised, Dean’s admission had clearly taken him by surprise. Eileen kept flickering her eyes between the two of them in what seemed to be confusion. But the best reaction of all came from Charlie, her jaw had dropped wide open. She was incredibly taken a back. Speechless for the first time in a long time. Cas found himself chuckling under his breath. 

“Nice to see you too, Charls,” Dean greeted in a playful manner, “Fly catching?” 

Dean perched himself on the edge of the booths seat, next to Cas. Cas shuffled over a bit to make space, before questioning if that was the right move. After all they were supposed to be dating, personal space was a myth for couples. And a myth for Sam and Eileen. 

Whilst their three friends began debating about when ‘Dean and Cas had happened,’ Dean tapped Cas shin with his foot to get his attention. Cas turned to see a smile spread across Dean’s face. He mouthed ‘good job’ to him before winking and turning away. Dean seemed to be good at keeping his cool in this situation and seemed perfectly able to lie to their friends. Cas, on the other hand, didn’t and was worried about when he’d crack. He didn’t really like lying to them. He felt bad. The only weight off his shoulders was that they’d never have to know the truth because in a month it’d be over. Dean would have Lisa and they could both pretend it had never happened. Dean must’ve sensed that Cas was anxious, as he placed a supportive hand on the top of his thigh. 

The group ate their meals in pretty much silence. Charlie kept flickering her eyes towards Dean and Cas, as she still tried to wrap her heard around ‘them’. The only time anyone spoke whilst eating was to laugh at Sam, who had just posted the most cringeworthy and cheesy Instagram post and caption ever. Something about how his meal (pancakes that were covered in more fruit than Dean had ever eaten in his life) were the only things here that were sweeter than him. Dean decided to keep some comments to himself. 

Cas and Dean’s fingers brushed against each other when they both reached for the salt, earning a knowing glance from Eileen. The contact sent a shiver down Cas’s spine, the butterflies remained in the pit of his stomach. There was an awkwardness over the meal, everyone still in shock over Cas and Dean’s revelation. Cas’s doubt was beginning to set in once more. 

However, after the waitress had come and cleaned their empty plates, Charlie perked up and the groups conversation sparked to life once more. 

“So, the school dance is coming up soon...” she stated with a smirk her gaze flickering around the table. Cas realised this was the starting motions of her plan. “Who is everyone going with?” 

Charlie had leant forward resting her elbows on the table the wide grin plastered on her face. She eyed up Sam and Eileen before turning a new attention to Dean and Cas. “I mean, I’d presume you two are going together,” she said with a glimmer in her eye. 

Neither Dean nor Cas answered but Charlie took their silence as confirmation. Dean had just stared at Cas, biting his lip in a what Cas would probably describe as a flirtatious manner. Cas knew it wasn’t real and was all part of their act but having Dean act in such a seductive manner towards him was such an unknown concept and he didn’t know how to feel. Didn’t know to respond. Didn’t know how to deal with it. Cas had not noticed that his cheeks had tinged a dark red. 

“And what about you two?” Charlie asked, her hands moving to sign her words. Cas was thankful that Charlie’s attention was now solely towards Sam and Eileen, “Got any plans for the dance?” 

Sam and Eileen replied almost in tandem. With Eileen explaining how she presumed she was going with Charlie, as friends, without a date and Sam saying he wasn’t even sure if he was going to go. Their hands almost moving in tandem. They both looked down instantly, embarrassed, when they noticed they’d answered so in sync. 

“You should go together,” Dean suddenly said in a blunt manner waving his finger between them both, before taking a sip of his coke. Sam and Eileen both turned to Dean, bewildered by his comment. Both of their cheeks started to turn rouge. Charlie also sharply turned her head to Dean, furious that he’d seemingly ruined her well thought out plan. Cas placed a hand on her arm to calm her down. 

“What? I’m just saying...” Dean trailed off, shrugging. “Bite the bullet. It worked for me.” 

He wiggled a finger between him and Cas as he spoke, which caused both Cas and Charlie to shift their focus towards him. They both realised Dean’s approach was maybe the best one. Being blunt and honest to Sam and Eileen was probably the best method. Pointing out how obvious it was that they had it really bad for each other might be the best way to get a result. Dean smiled at Charlie knowing she’d now caught on and appreciated his approach. At least if he was honest and upfront about this, it was one less thing he’d have to keep secret. 

“Yeah, you two can go together and then you can all finally help me find a girlfriend to go with!” Charlie exclaimed, clapping her hands with excitement. Everyone laughed at Charlie’s statement. It was a known fact that Charlie desperately wanted a girlfriend but no matter how hard they tried to find her the right person, something always seemed to fall in the way. Dean recounted the time he’d tried to get Charlie with one of his own exes, Anna Milton, and he was sure it would’ve been a great match until Anna spent more time talking about Dean and an apparent hatred, she now had for him, than paying any attention to Charlie. So maybe Dean wasn't the best match maker and maybe he and Anna had not ended on good terms. 

Charlie pouted in her seat. 

“You’ll find the one soon,” Dean reassured her, “Trust me. You only deserve the best anyway.”

When it was time to leave, Sam and Eileen separated from each other instantly after getting up out of their seats. Clearly attempted to ignore each other's presence to move past the awkwardness from earlier. Cas noticed the sly glances that Eileen was sending Sam’s way when she thought no one was looking and how it was clear Sam was trying to look almost everywhere but where Eileen was. They’d been caught red handed. He was thankful he’d never been this open and easy to read with his thoughts and feelings, or at least he liked to think he was a much more closed off person. Cas was also kind of glad he had this fake relationship as a safety blanket so no one could try meddle with his love life. Cas looked up, drawn out of his thoughts when Charlie nudged him. He hadn’t realised he’d been staring at Dean almost the whole time. 

Eileen and Charlie left together, with Charlie secretly giving a Dean and Cas a thumbs up, a smile beaming from ear to ear, she hoped and believed Dean’s encouragement would work. The plan was in motion. Sam was going to take a ride home with Dean and Cas, but hopped into the back seat of the impala without saying a sound. Cas presumed he was mad at Dean for what he’d revealed in the diner. Cas sat shotgun, beside Dean, and watched as Dean observed Sam in his rear mirror. Sam had a blank look on his face and seemed to be deep in thought over something. Dean stared the car engine with a roar, and turned to Cas before once again mouthing- ‘good job.’ 

They’d managed to trick their friends, and it all seemed believable. They hadn’t even needed to act like a couple much, and yet it had worked. Their friends believed them with ease. Cas wondered if their fake relationship may even end up being a vital key to pushing their other friends to get together. Maybe that was part of Dean’s plan all along. 

His optimistic thoughts should’ve made things better, taking the anxiety off his mind about the situation. But something still didn't feel quite right, he just couldn’t put his finger on it. The butterflies fluttered around in his stomach once more. 

_It’ll be okay,_ he told himself. _It’s only for a month._

**Notes for the Chapter:**

> So...Dean and Cas have started their act and are telling their friends, this can only go well right? And will Dean's comments finally push Sam and Eileen together?  
> Re writing parts of this au that are in the forms of texts and social media interactions is something I'm really enjoying but there is most likely grammatical errors, so for that I apologise.  
> This is the last update I'll post before Christmas, so I just want to say I hope that everyone who celebrates Christmas has a Merry Christmas! And if you don't I hope you have a great day!  
> Thanks for reading,  
> Love Leah <3


End file.
